1. Field of the Invention
The present invention relates to image recording members for recording an image by applying electricity, which are usable in recording such as receiving signal of facsimile, output of computor and its terminal equipments and datum of a various kind of measuring apparatuses for industry, medicine, bussiness and the like.
2. Description of the Prior Art
Recording of an electrical signal as an image has been increasing annually with development of facsimile and the like. Some conventional widely used methods are for example electrical discharge recording, electrolite recording and like methods.
In the electrical discharge recording method, a white pigment surface layer is provided on a black electrically conductive layer or an electrically conductive layer such as aluminum is provided on the black layer, and an electrical discharge is applied from a recording needle (hereinafter referred to as stylus) to remove the surface pigment so that the black layer may be revealed, forming an image. On the other hand, in accordance with the electrolite recording method, a paper is impregnated with an electrolite solution, kept in a wet state, and subjected to application of electricity and thus an image can be obtained. The resulting image is a colored substance formed by reaction of an ionized stylus metal and an electrolyte or a colored decomposition product formed by electrolysis of electrolyte by electricity applied from the stylus.
According to the electric discharge recording method, the surface layer is perforated by discharge heat generated by the stylus and therefore the recording method has several disadvantages such that an extremely strong irritating odor is generated, perforation dust off the surface layer is scattered, and consumption of the stylus is large. Furthermore, since the black layer is apt to be revealed by mechanical forces such as bending, pressure and so on, the paper easily becomes dirty. Furthermore, the surface layer is made thin so that discharge is easily generated and thus the black layer cannot be completely covered. Therefore, the paper is not white, but grey, resulting in bad appearance.
On the other hand, since the electrolite recording method is a wet type method, the durability of the recording paper is poor and image properties are deteriorated by blotting. In addition, the paper is subject to deformation such as wrinkle after recording. These disadvantages are inherent to the wet type of recording method.
Also a dry electrosensitive recording sheet is described in Japanese Pat. Nos. 22341/1963 and 29630/1969 wherein electrically reducable metal compounds are dispersed in an insulative resin and reduced to free metals by application of electricity, thereby forming an image. In that case, most of the metal compounds of relatively high electric conductivity are colored and non-colored metal compounds are of such low conductivity that they require chemical and physical treatments prior to application of electricity. However, such treatment causes coloration of metal compounds, thereby increasing the original color density of the recording paper. At the stage of application of electricity, discharge is caused and there occur disadvantages such as offensive odor is caused and consumption of the stylus is large. Furthermore, Japanese Pat. Nos. 5476/1967 and 13239/1967 disclose a method wherein an electrically conductive layer is formed on white or transparent compounds such as silica and the like by means of evaporation-deposit and thereafter they are dispersed in a matrix and subjected to application of electricity. However, this method has encountered some serious problems in the treatment stage. As stated above, recording members effective for forming an image have not been proposed.